Thanks Terry and Sergy.

>>My application has an external prg file that is used to execute a complex SET FILTER TO statement. I have a menu item to execute the prg as in DO SPECIAL_FILTERS. This works fine in the development environment, but in the runtime environment I get a 'file SPECIAL_FILTERS.PRG does not exist' error. This same error occurs if I include the full path to the file as in DO 'c:\program files\myapp\SPECIAL_FILTERS'. The file is definately there. Why can't the application see it?
>
>The runtime cannot run .PRG only .FXP. If you create the program on the fly than you have to COMPILE it.